EP0282930A3 - Method and device for phase-selective testing and/or measuring of test objects with eddy current techniques. - Google Patents

Method and device for phase-selective testing and/or measuring of test objects with eddy current techniques. Download PDF

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Publication number
EP0282930A3
EP0282930A3 EP88103938A EP88103938A EP0282930A3 EP 0282930 A3 EP0282930 A3 EP 0282930A3 EP 88103938 A EP88103938 A EP 88103938A EP 88103938 A EP88103938 A EP 88103938A EP 0282930 A3 EP0282930 A3 EP 0282930A3
Authority
EP
European Patent Office
Prior art keywords
phase
sin
cos
eddy current
current techniques
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP88103938A
Other languages
German (de)
French (fr)
Other versions
EP0282930A2 (en
Inventor
Bengt Hjalmar Törnblom
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TOERNBLOMS KVALITETSKONTROLL AB
Original Assignee
Tornbloms Kvalitetskontroll AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tornbloms Kvalitetskontroll AB filed Critical Tornbloms Kvalitetskontroll AB
Publication of EP0282930A2 publication Critical patent/EP0282930A2/en
Publication of EP0282930A3 publication Critical patent/EP0282930A3/en
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G01N27/9046—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents by analysing electrical signals

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Abstract

Method and device for phase-selective testing and/or mea­ suring of test objects, such as hot steel billets, with eddy current techniques with respect to surface cracks or other magnitudes, whereby at least one signal, e.g. A sin ωt, derived from this magnitude is detected by means of at least one phase-sensitive detector The output signal from an ordinary phase-controlled rectifier can be substantially described via, e.g. sin α and/or cos α functions in which α indicates the phase position of the control signal in relation to the input signal. By e.g. multiplying sinα by cos α, sin 2α or cos 2α functions are obtained which in turn can be multiplied to obtain the function sin 4α cor­ responding to narrow sensitivity lobes in the transducer's impedance plane, thus permitting effective separation of the various types of vector. The invention thus provides an improved conventional phase-sensitive detector, making it more phase-selective by adding at least one product and/or one quotient former.
EP88103938A 1987-03-17 1988-03-12 Method and device for phase-selective testing and/or measuring of test objects with eddy current techniques. Withdrawn EP0282930A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8701082 1987-03-17
SE8701082A SE456865B (en) 1987-03-17 1987-03-17 DEVICE FOR TESTING AND / OR SEATING, INCLUDING AT LEAST ONE PHYSICAL DETECTOR

Publications (2)

Publication Number Publication Date
EP0282930A2 EP0282930A2 (en) 1988-09-21
EP0282930A3 true EP0282930A3 (en) 1989-12-13

Family

ID=20367881

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88103938A Withdrawn EP0282930A3 (en) 1987-03-17 1988-03-12 Method and device for phase-selective testing and/or measuring of test objects with eddy current techniques.

Country Status (4)

Country Link
US (1) US4864235A (en)
EP (1) EP0282930A3 (en)
JP (1) JPS63308556A (en)
SE (1) SE456865B (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5006800A (en) * 1989-11-06 1991-04-09 General Electric Company Eddy current imaging apparatus and method using phase difference detection
FR2689637B1 (en) * 1992-04-06 1996-08-09 Aerospatiale METHOD AND INSTALLATION FOR NON-DESTRUCTIVE INSPECTION OF A WORKPIECE USING AN EDDY CURRENT SENSOR.
US5485084A (en) * 1993-05-10 1996-01-16 The Boeing Company Apparatus and method for detecting structural cracks using a movable detector
DK76293D0 (en) * 1993-06-25 1993-06-25 Brueel & Kjaer As displacement transducer
US5541510A (en) * 1995-04-06 1996-07-30 Kaman Instrumentation Corporation Multi-Parameter eddy current measuring system with parameter compensation technical field
DE10045715A1 (en) 2000-09-15 2002-03-28 Busch Dieter & Co Prueftech Method and device for testing a workpiece using eddy currents
WO2003034054A2 (en) * 2001-10-17 2003-04-24 Aea Technology Plc Method and apparatus for measuring material properties and lift-off components of an object using a magnetic probe
EP1952135A4 (en) * 2005-11-03 2011-12-14 Coastal Res Corp Comformable eddy current array
GB2456583B (en) * 2008-01-21 2012-09-05 Ge Inspection Technologies Ltd Eddy current inspection system and method of eddy current flaw detection

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3721896A (en) * 1971-12-23 1973-03-20 Nippon Kokan Kk Improved phase sensitive eddy current defect detector utilizing frequency doubling of detected signal prior to phase detection
US4061968A (en) * 1976-09-07 1977-12-06 Commissariat A L'energie Atomique Process of and apparatus for non-destructive eddy current testing involves the suppression of displayed lobes corresponding to fault parameters to be eliminated from the display
GB2086057A (en) * 1980-10-14 1982-05-06 Zetec Inc Eddy current tester

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE351493C (en) * 1971-12-28 1974-09-12 Nippon Kokan Kk Highly sensitive, fault detector operating with eddy currents
SE393867C (en) * 1975-07-09 1978-12-07 Tornblom Bengt Hjalmar DEVICE FOR TESTING AND / OR SATURATION OF CHANGES IN ELECTRICALLY CONDUCTIVE BODIES
SE8302738L (en) * 1983-05-16 1984-11-17 Bengt Hjalmar Tornblom DEVICE AND / OR SET BASED ON THE FREQUENCY PRINCIPLE
JPS60161556A (en) * 1984-01-31 1985-08-23 Sumitomo Metal Ind Ltd Method of eddy current flaw detection for continuously-cast piece
SE456043B (en) * 1984-02-10 1988-08-29 Bengt Hjalmar Tornblom SET AND DEVICE FOR TESTING AND / OR SATURING ELECTRICALLY CONDUCTIVE PROVOBECTS WITH REGARD TO CHANGES

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3721896A (en) * 1971-12-23 1973-03-20 Nippon Kokan Kk Improved phase sensitive eddy current defect detector utilizing frequency doubling of detected signal prior to phase detection
US4061968A (en) * 1976-09-07 1977-12-06 Commissariat A L'energie Atomique Process of and apparatus for non-destructive eddy current testing involves the suppression of displayed lobes corresponding to fault parameters to be eliminated from the display
GB2086057A (en) * 1980-10-14 1982-05-06 Zetec Inc Eddy current tester

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 10, no. 3, (P-418)[2060], 8th January 1986; & JP-A-60 161 556 (SUMITOMO KINOKU KOGYO K.K.) 23-08-1985 *

Also Published As

Publication number Publication date
US4864235A (en) 1989-09-05
SE8701082D0 (en) 1987-03-17
JPS63308556A (en) 1988-12-15
SE456865B (en) 1988-11-07
EP0282930A2 (en) 1988-09-21
SE8701082L (en) 1988-09-18

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